Various developments have been made in the control and design of an internal combustion engine to improve fuel efficiency while meeting ever stricter emission requirements. Improvements in valve timing arrangements have been made to control timing as well as a degree of opening of the intake and exhaust valves. As the internal combustion engine are required to operate at a range of speeds and loading conditions, the variable valve timing arrangement may allow the flow of gases into and from the engine to be tailored based on the operating conditions.
PCT Publication Number 2006/092312 discloses a variable mechanical valve control of an internal combustion engine including a bottom camshaft for adjusting a valve stroke and an opening and closing time, said valve control enabling an extremely compact transmission gear to be achieved between a push rod drive and the inlet and outlet valves, to reduce the number of components required for the transmission gear and to obtain a mechanical valve train that is completely variable, with a bottom camshaft. To achieve this, an intermediate lever is connected to a valve push rod by means of a shaft, in such a way that a slide gate roller, which is rotatably mounted on the shaft, is displaced by the camshaft in a slide gate. According to the invention, a first contact surface on the intermediate lever is supported in a reinforced manner by means of a spring on an eccentric shaft, or on a second contact surface and a lever is displaced using a working curve, said lever opening and/or closing the two-way gas valves. Elements are also provided, in particular on a lifter that is located on the push rod for the additional adjustment of the phase position of the valve elevations of the two-way gas valves with simultaneous play-free adjustment of the valve stroke and the invention is also equipped with elements for the additional independently controllable valve stroke opening and closing for each camshaft rotation.